A high frequency zero-voltage-transition (ZVT) synchronous buck converter for automotive applications

Automotive applications require a wide input voltage range (4.5 V to 42 V) and high frequency operation for point-of-load low power (5 W-25 W) converters. The conventional buck converter, currently being used for this application, is simple and cost effective but it is less efficient at high switching frequency (>MHz) and noisy due to its hard-switching operation. A zero-voltage-transition (ZVT) synchronous buck converter is proposed in this paper, which features ZVS for main switches, ZCS and low voltage rating for auxiliary switches. The operating principles including ZVS/ZCS mechanism, and detailed design considerations are presented. Experimental results from a 1 MHz prototype confirm its superior performance for low power automotive applications.